Role of trpv4 in trigeminally mediated nociception

三叉神经介导的疼痛障碍在分子水平上还不完全清楚。TRP（V）离子 通道在三叉神经感觉传导中起作用。TRPV 4是多模态的 例如通过机械、热和张力刺激激活，并且trpv 4基因的产物已经被 在三叉神经节感觉神经元及其外周投射中检测到， 由PI产生的，对有害的机械和张力刺激具有升高的阈值。临界 TRPV 4 * 三叉神经感觉神经元是否以及如何接受这些刺激的问题仍然没有解决 引发伤害性行为因此，本提案的目的是研究分子和细胞 frpv 4介导的三叉神经感觉伤害性渗透和机械刺激的转导机制 通过开发一种新的小鼠模型。待检验的假设是trpv 4基因是否 在三叉神经感觉神经元中的表达对于响应伤害性刺激的神经感觉传导是关键的。 刺激。具体而言，（1）将通过以下方法研究来自trpv 4 ~*~小鼠的三叉神经神经元的原代培养物： 膜片钳和Ca*+成像对张力和机械刺激的反应，通过激活 蛋白酶激活受体2（PAR-2），一种生理学相关的促痛觉通路，以及它们的 电压门控钠通道（INa）的“张力调节”和辣椒素反应;（2）与Aim（1）相同，但 对于来自感觉神经元特异性的、可诱导的trpv 4+小鼠的分离的感觉神经元;（3）感觉神经元特异性的、可诱导的trpv 4+小鼠的分离的感觉神经元; 将产生特异性的、可诱导的trpv 4 ^~小鼠，以测试这些小鼠对有害渗透刺激的反应。 和渗透调节辣椒素刺激三叉神经末梢，通过激活PAR-2调节。为 目的（1）-（2），原代培养的神经元将被遗传编码的荧光报告基因标记， 在小鼠的细菌T人工染色体转基因系中表达。对于目标（3），小鼠将经受 脑干三叉神经脊束核的伤害反应行为测定和c-FOS研究 刺激.因此，感觉传导和传递的伤害性三叉神经刺激的依赖性， trpv 4将在细胞水平上被解构，阐明三叉神经感觉神经的相对贡献。 neuron.此外，trpv 4如何在辣椒素反应的“张力调节”中发挥作用， 的iNa-。以及PAR-2对TRPV 4的调节。因此，我们的新小鼠模型将帮助我们更好地了解 三叉神经节神经元如何对伤害性刺激作出反应，以及trpv 4基因在其中起什么作用。 过程，希望开辟新的途径治疗三叉神经介导的疼痛。

Trigeminally-mediated pain disorders are incompletely understood at the molecular level. TRP(V) ion channels have been implicated to function in trigeminal sensory transduction. TRPV4 is multimodally activated, e.g. by mechanical, thermal and tonicity stimuli, and products of the trpv4 gene have been detected in trigeminal ganglion sensory neurons and their peripheral projections, f/pyf'' mice, previously generated by the PI, have an elevated threshold for noxious mechanical and tonicity stimuli. The critical question remains unresolved whether and howTRPV4* trigeminal sensory neurons transduce such stimuli that elicit nociceptive behavior. Thus, the objective of this proposal is to investigate molecular and cellular mechanisms of frpv4-mediated transduction of noxious osmotic and mechanical stimuli in trigeminal sensory neurons by development of a novel mouse model. The hypothesis to be tested is whether trpv4 gene expression in trigeminal sensory neurons is critical for neurosensory transduction in response to noxious stimuli. Specifically, (1) primary cultures of trigeminal neurons from trpv4~*~ mice will be investigated by patch-clamp and Ca*+ imaging in response to tonicity and mechanical stimuli, modulated by activation of proteinase-activated receptor 2 (PAR-2), a physiologically relevant pro-algesic pathway, and for their "tonicity-tuning" of voltage-gated sodium channels (lNa) and capsaicin-response; (2) same as in Aim (1),but for dissociated sensory neurons from sensory-neuron-specific, inducible trpv4'~ mice; (3) sensdry-neuron- specific, inducible trpv4^~ mice will be generated to test the response of these mice to noxious osmotic stimuli and osmotic modulation of capsaicin stimuli of trigeminal peripherals, modulated by activation of PAR-2. For Aims (1)-(2), primary cultured neurons will be labeled by a genetically-encoded fluorescent reporter gene, expressed in a bacterialTartificial chromosometransgenic line of mice. For Aim (3), mice will be subjected to nocifensive behavioral assays and c-FOS studies of the brain stem trigeminal spinal nucleus in response to stimulation. Thus, the dependence of sensory transduction and transmission of noxious trigeminal stimuli on trpv4 will be deconstructed at the cellular level, clarifying the relative contribution of the trigeminal sensory neuron. Moreover, light will be shed on how trpv4 functions in "tonicity-tuning" of the capsaicin response and of iNa-. and on modulation of TRPV4 by PAR-2. Thus, our new mouse model will help us better understand how trigeminal ganglion neurons respond to noxious stimuli and which role the trpv4 gene plays in this process, hopefully opening up new avenues for treatment of trigeminally-mediated pain.